College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci China Life Sci. 2021 Dec;64(12):2175-2185. doi: 10.1007/s11427-020-1917-x. Epub 2021 Apr 22.
The bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), belonging to Xanthomonas sp., causes one of the most destructive vascular diseases in rice worldwide, particularly in Asia and Africa. To better understand Xoo pathogenesis, we performed genome sequencing of the Korea race 1 strain DY89031 (J18) and analyzed the phylogenetic tree of 63 Xoo strains. We found that the rich diversity of evolutionary features is likely associated with the rice cultivation regions. Further, virulence effector proteins secreted by the type III secretion system (T3SS) of Xoo showed pathogenesis divergence. The genome of DY89031 shows a remarkable difference from that of the widely prevailed Philippines race 6 strain PXO99A, which is avirulent to rice Xa21, a well-known disease resistance (R) gene that can be broken down by DY89031. Interestingly, plant inoculation experiments with the PXO99A transformants expressing the DY89031 genes enabled us to identify additional TAL (transcription activator-like) and non-TAL effectors that may support DY89031-specific virulence. Characterization of DY89031 genome and identification of new effectors will facilitate the investigation of the rice-Xoo interaction and new mechanisms involved.
细菌病原体稻黄单胞菌 pv. 稻种（Xoo），属于黄单胞菌属，可引起全球范围内最具破坏性的水稻血管疾病之一，尤其是在亚洲和非洲。为了更好地了解 Xoo 的致病机制，我们对韩国 1 号菌株 DY89031（J18）进行了基因组测序，并分析了 63 株 Xoo 菌株的系统发育树。我们发现，丰富的进化特征多样性可能与水稻种植区有关。此外，由 Xoo 的 III 型分泌系统（T3SS）分泌的毒力效应蛋白表现出致病分化。与广为人知的菲律宾 6 号菌株 PXO99A 相比，DY89031 的基因组显示出显著差异，后者对水稻 Xa21 无毒，而 Xa21 是一种著名的抗病（R）基因，可被 DY89031 破坏。有趣的是，用表达 DY89031 基因的 PXO99A 转化株进行植物接种实验，使我们能够鉴定出可能支持 DY89031 特异性毒力的其他 TAL（转录激活样）和非 TAL 效应子。DY89031 基因组的特征描述和新效应子的鉴定将有助于研究水稻与 Xoo 的相互作用和新的参与机制。
